Exemplary embodiments relate to an optical module, an optical transceiver, and an optical communication system including the same.
Digital transmission systems using optical fibers are currently most widely used in wired communication fields. When a wired communication network or a wired/wireless integrated subscriber communication network is operated, wired communication network performance may be determined by an optical transceiving module (or an optical transceiver) and other optical components.
An optical transceiver of a typical wired optical communication network may include an optical transmission module and an optical receiving module, and the optical transmission module may include a light-emitting device and an optical modulator.
Generally, an infrared (IR) laser diode (LD) having an oscillation wavelength region of about 1 μm is used as a light-emitting device for an optical communication network using a silica optical fiber as a transmission line. The light-emitting device and an optical modulator may be connected via a free space by using a lens, may be connected by using a waveguide formed of a material, such as a polymer, or may be connected by forming a waveguide on a wafer during a process of integrally forming the light-emitting device and the optical modulator.
Since the LD may output high-output high-quality light (e.g., light having a small spectrum half width), the LD is advantageous as a light source for transmitting a long-distance high-capacity light signal. However, since operating characteristics of the LD are sensitive to ambient temperature, a temperature compensation device (e.g., a thermoelectric cooler (TEC)) is required to obtain stable operation.
Furthermore, when emitted light is reflected by the surroundings and incident on the LD, the operating characteristics of the LD become very unstable. Thus, the use of an optical isolator is inevitable, and manufacturing costs of the LD itself are high.
Recently, the Internet of Things (IoT) era is coming with the development of network technology, sensor technology, radio-frequency identification (RFID) technology, and software technology. Optical communication networks including optical transceiving modules are necessarily required to connect a large number of devices. Accordingly, the development of optical transceiving modules capable of operating without a temperature compensation device and an optical isolator in an extreme environment of about −50° C. to about 150° C. is required. Here, a temperature range from about −50° C. to about 150° C. is an allowable temperature range for normal operations of a silicon (Si) integrated circuit (IC) that is used for various electronic circuits.
However, the LD is problematic in that reliability cannot be guaranteed in various temperature environments without a temperature compensation device and an optical isolator, and the LD is high-priced.